Synopsis

This report analyzes severe weather events data from the NOAA Storm Database, spanning 1950 to November 2011, to identify the types of events that significantly affect population health and have substantial economic consequences in the United States. Initial data processing involved cleaning and structuring a vast dataset to ensure accurate analysis. The study identifies key weather events causing the highest mortality, injuries, and economic losses, presenting the findings through descriptive statistics and visualizations. Results highlight specific severe weather types that require priority in resource allocation and preparedness strategies by municipal managers.

Data Processing

Load Necessary Libraries

library(dplyr)
library(ggplot2)
library(readr)
library(data.table)

Load the Data

# Loading the compressed CSV file directly using data.table for efficiency
storm_data_raw <- fread("https://d396qusza40orc.cloudfront.net/repdata%2Fdata%2FStormData.csv.bz2")

head(storm_data_raw)
##    STATE__           BGN_DATE BGN_TIME TIME_ZONE COUNTY COUNTYNAME  STATE
##      <num>             <char>   <char>    <char>  <num>     <char> <char>
## 1:       1  4/18/1950 0:00:00     0130       CST     97     MOBILE     AL
## 2:       1  4/18/1950 0:00:00     0145       CST      3    BALDWIN     AL
## 3:       1  2/20/1951 0:00:00     1600       CST     57    FAYETTE     AL
## 4:       1   6/8/1951 0:00:00     0900       CST     89    MADISON     AL
## 5:       1 11/15/1951 0:00:00     1500       CST     43    CULLMAN     AL
## 6:       1 11/15/1951 0:00:00     2000       CST     77 LAUDERDALE     AL
##     EVTYPE BGN_RANGE BGN_AZI BGN_LOCATI END_DATE END_TIME COUNTY_END COUNTYENDN
##     <char>     <num>  <char>     <char>   <char>   <char>      <num>     <lgcl>
## 1: TORNADO         0                                               0         NA
## 2: TORNADO         0                                               0         NA
## 3: TORNADO         0                                               0         NA
## 4: TORNADO         0                                               0         NA
## 5: TORNADO         0                                               0         NA
## 6: TORNADO         0                                               0         NA
##    END_RANGE END_AZI END_LOCATI LENGTH WIDTH     F   MAG FATALITIES INJURIES
##        <num>  <char>     <char>  <num> <num> <int> <num>      <num>    <num>
## 1:         0                      14.0   100     3     0          0       15
## 2:         0                       2.0   150     2     0          0        0
## 3:         0                       0.1   123     2     0          0        2
## 4:         0                       0.0   100     2     0          0        2
## 5:         0                       0.0   150     2     0          0        2
## 6:         0                       1.5   177     2     0          0        6
##    PROPDMG PROPDMGEXP CROPDMG CROPDMGEXP    WFO STATEOFFIC ZONENAMES LATITUDE
##      <num>     <char>   <num>     <char> <char>     <char>    <char>    <num>
## 1:    25.0          K       0                                            3040
## 2:     2.5          K       0                                            3042
## 3:    25.0          K       0                                            3340
## 4:     2.5          K       0                                            3458
## 5:     2.5          K       0                                            3412
## 6:     2.5          K       0                                            3450
##    LONGITUDE LATITUDE_E LONGITUDE_ REMARKS REFNUM
##        <num>      <num>      <num>  <char>  <num>
## 1:      8812       3051       8806              1
## 2:      8755          0          0              2
## 3:      8742          0          0              3
## 4:      8626          0          0              4
## 5:      8642          0          0              5
## 6:      8748          0          0              6

Data Cleaning and Preparation

# Subset data for relevant columns
storm_data <- storm_data_raw[, .(EVTYPE, FATALITIES, INJURIES, PROPDMG, PROPDMGEXP, CROPDMG, CROPDMGEXP)]

# Convert EVTYPE to factor
storm_data$EVTYPE <- as.factor(storm_data$EVTYPE)

# Handle damage exponent to convert all damage figures to actual values
storm_data$PROPDMG <- storm_data$PROPDMG * 10^(nchar(storm_data$PROPDMGEXP)-1)
storm_data$CROPDMG <- storm_data$CROPDMG * 10^(nchar(storm_data$CROPDMGEXP)-1)

# Clean up the exponents now that they are no longer needed
storm_data <- storm_data[, .(EVTYPE, FATALITIES, INJURIES, PROPDMG, CROPDMG)]

head(storm_data)
##     EVTYPE FATALITIES INJURIES PROPDMG CROPDMG
##     <fctr>      <num>    <num>   <num>   <num>
## 1: TORNADO          0       15    25.0       0
## 2: TORNADO          0        0     2.5       0
## 3: TORNADO          0        2    25.0       0
## 4: TORNADO          0        2     2.5       0
## 5: TORNADO          0        2     2.5       0
## 6: TORNADO          0        6     2.5       0

Results

Analysis of Health Impact

# Sum fatalities and injuries by event type
health_impact <- storm_data[, .(Total_Fatalities = sum(FATALITIES),
                                Total_Injuries = sum(INJURIES)), by = EVTYPE]

# Sort to find the most harmful events
health_impact <- health_impact[order(-Total_Fatalities, -Total_Injuries)]

head(health_impact,10)
##             EVTYPE Total_Fatalities Total_Injuries
##             <fctr>            <num>          <num>
##  1:        TORNADO             5633          91346
##  2: EXCESSIVE HEAT             1903           6525
##  3:    FLASH FLOOD              978           1777
##  4:           HEAT              937           2100
##  5:      LIGHTNING              816           5230
##  6:      TSTM WIND              504           6957
##  7:          FLOOD              470           6789
##  8:    RIP CURRENT              368            232
##  9:      HIGH WIND              248           1137
## 10:      AVALANCHE              224            170
# Plot for health impacts
ggplot(health_impact[1:10], aes(x = reorder(EVTYPE, -Total_Fatalities), y = Total_Fatalities)) +
  geom_bar(stat = "identity", fill = "gray") +
  theme_minimal() +
  theme(axis.text.x = element_text(angle = 45, hjust = 1)) +  # Rotating labels 45 degrees
  labs(title = "Top 10 Weather Events by Fatalities", x = "Event Type", y = "Number of Fatalities")

Economic Consequences Analysis

# Sum property and crop damage by event type
economic_impact <- storm_data[, .(Total_Property_Damage = sum(PROPDMG),
                                  Total_Crop_Damage = sum(CROPDMG)), by = EVTYPE]

# Sort to find the events with greatest economic consequences
economic_impact <- economic_impact[order(-Total_Property_Damage, -Total_Crop_Damage)]

head(economic_impact,10)
##                 EVTYPE Total_Property_Damage Total_Crop_Damage
##                 <fctr>                 <num>             <num>
##  1:            TORNADO             3212255.5         100018.52
##  2:        FLASH FLOOD             1419938.3         179200.46
##  3:          TSTM WIND             1335965.6         109202.60
##  4:              FLOOD              899932.2         168037.88
##  5:  THUNDERSTORM WIND              876842.4          66791.45
##  6:               HAIL              688642.1         579593.58
##  7:          LIGHTNING              603349.1           3580.61
##  8: THUNDERSTORM WINDS              446112.3          18677.73
##  9:          HIGH WIND              324731.6          17283.21
## 10:       WINTER STORM              132720.6           1978.99
# Plot for economic impacts
ggplot(economic_impact[1:10], aes(x = reorder(EVTYPE, -Total_Property_Damage), y = Total_Property_Damage)) +
  geom_bar(stat = "identity", fill = "steelblue") +
  theme_minimal() +
  theme(axis.text.x = element_text(angle = 45, hjust = 1)) +  # Rotating labels 45 degrees
  labs(title = "Top 10 Weather Events by Property Damage", x = "Event Type", y = "Total Property Damage ($)")